ServletContext

ServletContext 

在web.xml 里面配置ServletContext可以实现多个servlet共享：

eg:
  <context-param>
  <param-name>driver</param-name>
  <param-value>com.mysql.jdbc.Driver</param-value>
 </context-param>
 <context-param>
  <param-name>url</param-name>
  <param-value>jdbc:mysql://localhost:3306/jdbc</param-value>
  </context-param>

在servlet里面可以这样写：

ServletContext sxt = this.getServletContext();

String driver = sxt.getInitParameter("driver");

String url = sxt.getInitParameter(“url");